Trials by innovative canegrowers in Queensland have halved the run-off of herbicides and fertiliser from their farms, according to results being released during a two-day grower forum that began in Cairns today.

Key points:

Initial trials show some farms have halved herbicide and nutrient run-off

WWF Australia said the measures could help improve the health of the Great Barrier Reef

WWF Australia said if the measures were proven over a longer period and adopted industry-wide, they had the potential to greatly improve the health of the Great Barrier Reef while also boosting farm productivity.

The organisation is one of the backers of Project Catalyst, which supports 80 canegrowers who are testing new methods of improving farm efficiency and reducing pollutant runoff.

"The misconception is that farmers are the bad blokes and we're just pumping it on and pumping it into the rivers and waterways," said Mario Raccanello, one of the 80 participating canegrowers.

"There's not that much money in cane, so if we were that inefficient we'd be out the door straight away. So we don't waste fertiliser and chemicals."

But reducing run-off is a challenge when you live in one of the wettest places in Australia.

Using cow manure to make bio-fertiliser

Mr Raccanello has a 370-hectare cane farm at Tully, in tropical north Queensland.

Faced with escalating fertiliser bills and depleted soils, Mr Raccanello has been experimenting with making his own bio-fertiliser, based on cow manure. Project Catalyst helped with expert advice.

Joe Muscat farms 600 kilometres further south at Oakenden near Mackay.

He said it was crucial the Australian cane industry increased its productivity.

"Production in Australian has flatlined, that's being kind — probably really it's in decline," he said.

Mr Muscat went to Brazil — the world's largest sugar producer — on a 2013 Nuffield farming scholarship.

He is now understood to be the first canegrower in Australia to trial a Brazilian farming method which interplants sugar cane and legumes — in his case, two rows of cane to every six rows of mung beans.

Compost is injected below the topsoil so there is less chance of losing its nutrients.

The method is all about improving soil quality, Mr Muscat said.

In areas where it is used widely "the Brazilians are claiming 10–15 per cent increase in productivity", Mr Muscat said. "That's really significant."

Mr Muscat will not have initial results from his trial until next year.

Project Catalyst aiming to deliver solutions for farmers and reef

But Rob Cocco from Reef Catchments Limited said that since Project Catalyst began six years ago it had improved the quality of 150 billion litres of water flowing into the reef lagoon.

He conceded that was only about 1 per cent of the total flow from the catchment area.

"We hope we'll see the transition of these practices to ultimately become mainstream adoption by producers right across the industry, and if that occurs we obviously expect significant increases in the volume of improved water," he said.

"But what can happen is that measures proven viable could be taken up by hundreds if not thousands of farmers."

There are 4,000 cane-growing businesses in Australia.

"If we can find a solution with less fertiliser running off farms, firstly the farmer is better off because fertiliser is on crop, and secondly the reef is better off, because it's not polluting the reef and leading to crown of thorns starfish outbreaks," Mr Hoobin said.

"So this is probably the challenge for the Great Barrier Reef, and if we can knock this one off we'll actually give the reef a good chance of recovering."

Other supporters of Project Catalyst include the Coca-Cola Foundation, Bayer CropScience, and government research agencies.